The present invention relates to the technical field of composite materials comprising a warp-knitted textile panel, preferably including weft-inserted weft yarns, and coated on at least one of its faces with a layer of at least one polymer material.
Warp-knitted textile panels are thus used as reinforcement for the layer of at least one polymer material. These composite materials may be used as a protective cover, e.g. for swimming pools, as an advertising medium, as a luggage cover, as a roofing element, in particular for terraces, or as a self-adhesive strip. For a self-adhesive strip, the textile panel includes a film that is suitable for coming into contact with the adhesive layer without adhering to it.
A self-adhesive strip is known that includes a warp-knitted textile panel having weft yarns inserted at regular intervals. A drawback of that knitted panel is that it presents first and second opposite faces that are uneven. The lack of planeness of those faces makes it necessary to use a relatively large amount of polymer material in order to even out the faces and to obtain a composite material that is homogeneous. Furthermore, the shape of the wales of the knitted panel is visible in the adhesive layer, and that gives an unattractive aspect to the composite material.
This aspect may considerably hamper use of this type of knitted panel, which consists of composite material having a decorative function, such as for protective covers for swimming pools, luggage covers, advertising media, or roofing elements. Specifically, the wales create a stripy effect on the surface of composite material.
EP 0 978 583 A1 relates to an article having loops projecting from its surface suitable for acting as female fastener members in a fastener device of the hook and loop type. As shown in FIGS. 9 to 11 in particular, the wales are formed by means of two guide bars of a knitting machine working at the same time and on each course and not in alternation in such a manner that the first yarn and the second yarn form stitches on each of the courses and not on every other course. The wales present loops at regular intervals and thus form bulky projections. The surface of the material including those wales is therefore not even and plane and takes away a large amount of any polymer material layer that is applied to said surface, and does so in uneven manner.
The present invention thus provides a warp-knitted textile panel having first and second faces presenting planeness and uniformity that are improved, limiting the stripy effect of the wales in the layer of at least one polymer material, while satisfying the criteria for strength in the warp and weft directions in order to provide its primary function of reinforcement.